Deliver IPC messages together with SwapCompositorFrame

content/renderer/queue_message_swap_promise.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/renderer/queue_message_swap_promise.h"
+#include "content/renderer/gpu/frame_swap_message_queue.h"
+#include "ipc/ipc_sync_message_filter.h"
+
+namespace content {
+
+QueueMessageSwapPromise::QueueMessageSwapPromise(
+    scoped_refptr<IPC::SyncMessageFilter> message_sender,
+    scoped_refptr<content::FrameSwapMessageQueue> message_queue,
+    int source_frame_number)
+    : message_sender_(message_sender),
+      message_queue_(message_queue),
+      source_frame_number_(source_frame_number),
+#ifndef NDEBUG
+      completed_(false)
+#endif
+{
+  DCHECK(message_sender_.get());
+  DCHECK(message_queue_.get());
+}
+
+QueueMessageSwapPromise::~QueueMessageSwapPromise() {
+  // The promise should have either been kept or broken before it's deleted.
+  DCHECK(completed_);
+}
+
+void QueueMessageSwapPromise::DidSwap(cc::CompositorFrameMetadata* metadata) {
+  DCHECK(!completed_);
+  message_queue_->AdvanceToFrame(source_frame_number_);
+  // The OutputSurface will take care of the Drain+Send.
+  PromiseCompleted();
+}
+
+void QueueMessageSwapPromise::DidNotSwap(DidNotSwapReason reason) {
+  DCHECK(!completed_);
+  // This will also send messages explicitly queued with the WITH_NEXT_SWAP
+  // policy. It makes sense to send them if reason == SWAP_FAILS, but they may
+  // end up being sent prematurely if reason == COMMIT_FAILS.
+  ScopedVector<IPC::Message> messages;
+  message_queue_->AdvanceToFrame(source_frame_number_);
+  scoped_ptr<content::FrameSwapMessageQueue::SendMessageScope>
+      send_message_scope = message_queue_->AcquireSendMessageScope();
+  message_queue_->DrainMessages(&messages);
+  for (ScopedVector<IPC::Message>::iterator i = messages.begin();
+       i != messages.end();
+       ++i) {
+    message_sender_->Send(*i);
+  }
+  messages.weak_clear();
+  PromiseCompleted();
+}
+
+void QueueMessageSwapPromise::PromiseCompleted() {
+#ifndef NDEBUG
+  completed_ = true;
+#endif
+}
+
+}  // namespace content